This invention relates to new and useful improvements in stubble conditioning devices particularly designed for use with farm implements such as swathers, windrowers or the like in which the grain is cut with a predetermined length of straw and then deposited in a swath behind the machine so that it can be air conditioned prior to threshing.
It will be appreciated that the straw length of growing grain varies depending upon the variety, the type of grain and weather conditions encountered during the growing season and such straw lengths may vary, for example, from relatively short up to a height of approximately 30 inches.
From a theoretical standpoint, it will be appreciated that the shortest possible length of straw is desired upon the grain heads after swathing and prior to threshing so that the volume of straw does not interfere with the threshing action of a combine. For example if the stubble is cut relatively short by the swather, then a relatively large volume of straw will have to be processed by the thresher or combine which interferes with efficient action of the concave and separation assemblies.
While it is appreciated that the cutter bar assemblies of swathers can be raised so that the straw length can be controlled, nevertheless it will also be appreciated that it is not desirable to leave relatively long straw stubble which although advantageous to fertility, nevertheless causes considerable problems by not supporting the windrow adequately.
Furthermore, relatively long straw stubble does not support a swath efficiently, because the weight of the swath forces the long stubble downwardly so that good air circulation is not possible. Another disadvantage of long straw stubble is the difficulty in picking up the swath therefrom when threshing or combining due to buckling and flattening of the swath or windrow supporting stubble.
Known prior art includes U.S. Pat. No. 1,905,409 which shows a "trough swather" but without any conditioning of the stubble in the swath path and U.S. Pat. No. 2,850,681 which teaches a similar result. U.S. Pat. No. 1,944,750 illustrates a system which includes the laying of a mat of straw on the stubble in order to support the swath which is then subsequently laid on top of the mat.
Canadian Pat. No. 328857 is also a "trough swather" giving a result similar to U.S. Pat. No. 1,905,409.
Canadian Pat. No. 321071 shows a structure in which the rear edge of a stationary pan engages the tops of the stubble and deflects them over to receive the swath, the weight of which proposes to hold the ends in the bent position. However, this is problematical and certainly cannot be called conditioning of the stubble.